1. Field of the Invention
The present invention relates to a patient-specific acetabular guide, and more particularly to a patient-specific acetabular guide used in a hip-joint replacement surgery and method of manufacturing the same. The patient-specific acetabular guide can be used in connection with various other instruments to facilitate guided reaming procedure of an acetabulum of a pelvis of a specific patient and a guided procedure of insertion and implantation of an acetabulum implant or acetabular cup in the acetabulum.
2. Description of the Prior Art
A conventional patient-specific acetabular guide disclosed in U.S. Pat. No. 8,608,749 issued to Meridew et al. on Dec. 17, 2013 comprises a patient-specific body covering the acetabular fossa at the center of the acetabulum and a guiding element having an elongated bore with a patient-specific alignment axis configured to be central to the acetabular cup and perpendicular to the acetabular cup's surface when the acetabular guide is positioned to the acetabulum. The elongated bore of the guiding element is used for leading a tool to drill the acetabulum along the patient-specific alignment axis.
The acetabular guide also includes two marker elements each having an elongated bore for guiding marker pin. The marker pins are used for supporting a secondary guide which is used to adjust the orientation and position of the acetabular cup when the acetabular cup is placed onto the acetabulum. The marker elements both extend upwardly from the patient-specific body. The patient-specific body designed by using a three-dimensional model of the acetabulum and surrounding pelvic area of the patient includes an inner portion from which the guiding element extends, and an outer portion extending from the inner portion and configured to extend over a portion of the acetabular rim. The inner portion is designed to engage the acetabulum. The outer portion extends sufficiently beyond the rim to the periacetabular area of the pelvis to accommodate the marker elements.
The patient-specific body also has an underside three-dimensional engagement surface that is custom-made or patient-specific to conform to and mirror complementary surface of the acetabulum, rim or other periacetabular surface of the pelvis of the specific patient. The engagement surface of the patient-specific body enables the acetabular guide to nest or closely mate relative to the complementarily acetabular surface of the patient. However, the process of placing the acetabular guide is not described and malposition of the acetabular guide is easily produced due to the hemispherical shape of the acetabular during manually placing the acetabular guide to the acetabulum of the patient.
Hence, it is desirable to provide an improved patient-specific acetabular guide and method of manufacturing the same to overcome the aforementioned disadvantages.